Flood mitigation guide consists of action items organized in a checklist and provided in Excel format. The following water treatment system components are covered:
Cost Key (Provides relative costs - actual costs may differ) $ - Little to no cost. Some internal level of effort required, but no contractor support needed. $$ - Moderate cost/complexity. Likely involves contractual costs. $$$ - High cost/complexity. Will require one or more contractors to implement this option.
Flood Mitigation for Buildings
1. Prevent Buildings from flooding.
Cost
a. Caulk and/or seal wall and floor penetrations.
$
b. Install backflow prevention devices on sewers, drains and other buildings.
$
c. Install waterproof protection (e.g., removable/semi-permanent structures, sealed doors, shields) for building entry points (e.g., windows, doors, garages).
$$
d. Install floodwalls, levees or berms around buildings.
$$$
2. Protect critical components if buildings do flood.
a. Train staff how and when to shut down and start up power and gas supplies, electrical controls, operating systems and other equipment in system facilities.
$
b. Identify locations outside the flood zone where utility equipment (e.g., heavy equipment, vehicles, replacement parts, backup generators, pumps) can be stored safely, permanently or temporarily, to prevent damage from flood waters or debris.
$
c. Have an alternative access plan in case normal access to buildings is blocked. Consult with other entities (e.g., Department of Transportation) to consider alternate road/transportation options (e.g., watercraft).
$
d. Elevate or relocate equipment (e.g., computers, desks, work benches) to prevent damage if water does enter the facility (i.e., move control centers and/or laboratories to a second floor).
$$-$$$
e. Maintain a cache of spare parts.
$-$$$
3. Maintain operations when the electrical grid is down.
a. Maintain a generator above flood levels
$
4. Maintain continuity of operations during flooding.
a. Regularly backup electronic and paper files outside the flood zone either on-site (e.g., an upper floor) or off-site. Include all permits and compliance documentation, designs and as-built drawings, process diagrams, operations and maintenance (O&M) records, standard operating procedures, process and equipment manuals, material safety data sheets, asset management data, purchasing records, operations data, customer records and other critical information.
$
b. Have the capability to operate remotely in case buildings are inaccessible.
$$$
c. Establish interconnections or other partnership opportunities to share resources with neighboring water utilities.
$$-$$$
Flood Mitigation for Chemical and Other Storage
Mitigation Options for Chemical and Other Storage
Cost
a. Elevate or relocate tank platforms above flood levels (e.g., 100- and/or 500-year flood) or install physical barriers around the tanks.
$-$$$
b. Secure tanks to platforms (i.e., bolt tanks down).
$
c. Install larger capacity chemical storage tanks to ensure a sufficient supply through and beyond an emergency until the supply chain is restored.
$
d. Establish emergency contract provisions with various fuel vendors and chemical suppliers and inform them of estimated fuel/chemical needs (type, volume and frequency). Work with your local emergency management agency to prioritize chemical/fuel needs.
$$
e. Ensure chemicals and fuels are topped off in advance of a potential flood.
$-$$
f. For systems that work on groundwater well supply, procure or get access to a portable chlorinator.
$-$$
Flood Mitigation for Instrumentation and Electrical Controls
1. Protect instrumentation and electrical controls from flood damage.
Cost
a. Elevate individual instrumentation/controls, control centers and MCUs or relocate to remote locations outside of the flood zone.
$$
b. Maintain a cache of spare parts to restart operations as soon as possible.
$-$$
c. Purchase and have available portable equipment if permanent equipment becomes disabled.
$$
d. Train staff to shut down electrical equipment and controls (e.g., SCADA systems, computers, field instruments) prior to a flood to minimize damage.
$$
e. Replace instrumentation and control enclosures with waterproof models.
$-$$$
2. Maintain continuity of operations (e.g., redundant controls at another location) if instrumentation and controls are damaged by a flood.
a. Have redundant controls at another location and/or remote access capabilities.
$$
b. Train staff and plan for manual operation of your water system.
$
Flood Mitigation for Power Supply
1. Long before a flood, take measures to reduce the duration of power outages.
Cost
a. Prepare a list of key utility facilities (e.g., intake works, pump stations, treatment facility) that require critical power restoration and include the physical locations of the facilities and their corresponding power company account numbers. Provide this information to the power company during an outage to expedite electricity restoration.
$
b. Talk with your local emergency management agency and local power utility to increase the priority of power restoration for your utility’s facilities
$
c. Working with the power utility, consider installation of two independent power feeds to your utility, elevating substations and/or ways to avoid downed power lines.
$$
d. Establish more reliable connection to power source (e.g., install substation expressly for your utility or a dedicated feeder between the power station and the treatment plant).
$$$
2. Secure backup generators.
a. For your electrical requirements, document the size and type of backup generator that you need including voltage, phase configuration, horsepower/amperage, fuel, etc.
$
b. Have pump stations wired to accept a portable generator. Ensure that “quick connect” capability is installed and ready, and that on-site personnel are trained.
$
c. Arrange to get portable generators in an emergency by maintaining a call list of multiple vendors that rent portable generators, entering into an agreement with a particular vendor or joining a mutual aid network (e.g., Water/Wastewater Agency Response Network [WARN]) to allow sharing of backup generators. During widespread flooding events, demand and competition for portable generators will be high.
$
d. Procure and install your own portable or permanent generators. Consider multi-fuel generators.
$$$
3. Secure a source of fuel for backup generators.
a. Fill fuel storage tanks in anticipation of flooding.
$
b. Establish an agreement with your fuel supplier and provide estimates of fuel needs (e.g., volume and frequency) in the event of a power outage. Also, secure a list of alternative fuel suppliers. Maintain communication with your local emergency management agencies for priority in getting fuel supplies.
$
c. Install fuel tanks on your utility’s vehicles and train staff in moving the utility’s fuel in an emergency.
$$
d. Perform an energy audit of your facility to identify energy saving opportunities via operations and equipment modifications. Implement recommendations of the audit (e.g., replace equipment with energy efficient models) to extend the life of your backup power supply.
$$
e. Install additional and/or larger fuel storage tanks.
$$
4. Install an alternative energy system.
a. Install solar panels or wind turbines to reduce dependence on the electrical grid and to potentially supplement your backup power supply (ensure your utility has the proper technical switches).
$$$
b. Install cogeneration units and/or a waste heat recovery system at wastewater treatment plants to reduce or eliminate dependence on the grid.
a. Train staff to shut down electrical equipment (e.g., Supervisory Control and Data Acquisition [SCADA] systems, computers, field instruments) prior to a flood event to minimize potential damage from flood waters.
$
b. Develop “start and connect” checklists specific to each piece of equipment.
$
c. Equip generators and motors with disconnect fittings that can be removed before a flood and then restored.
$
d. Evaluate existing electrical panels to determine the best method of connecting external portable generators to the facility or to individual pieces of equipment.
$
e. Replace/upgrade electrical connections/motor controls/junction boxes with watertight panels.
$$
f. Relocate or elevate electrical vaults and service panels outside of the flood zone
$$$
Flood Mitigation for Water Intake, Distribution and Storage of Surface Water Utilities
1. Prevent structures from flooding.
Cost
a. Relocate or elevate pump house and distribution system appurtenances that are in the flood zone.
$$$
2. Protect critical components if intake, distribution and storage of finished water do flood.
a. Protect or reinforce surface water intake structures from floating debris, erosion and siltation to prevent damage or blockages during floods. Install jetty or breakwater to divert debris/silt away from structure. Install/upgrade screen at the intake to prevent debris blockages.
$$
b. Waterproof, relocate or re-enforce distribution system appurtenances (i.e., fire hydrants, valve vaults) susceptible to flooding or damage from debris.
$$
c. Install submersible pumps or waterproof pump motors.
$$
d. Ensure that distribution lines across streams are sufficiently below streambed.
$$-$$$
3. Maintain delivery of suitable process water during flooding.
a. Sign up for U.S. Geological Survey (USGS) alerts for stream and river gauges: • WaterAlert – Select gauges of interest, and USGS will send an email/Short Messaging Service (SMS; i.e., text) message when parameters exceed userdefined thresholds. • WaterNow – Receive current conditions for water data at a specific gauge directly to your mobile phone or email.
$
b. Install monitoring equipment upstream of intakes to provide an early warning of raw water conditions (e.g., turbidity, flow) if no state or federal monitoring is available. Adjust the treatment process as necessary (e.g., chemical addition, residence time) to account for higher contaminant loading or increased turbidity.
$$
c. Have an alternative access plan in case normal access to intake structure and/or pump house is blocked. Consult with other entities (e.g., Department of Transportation) to consider alternate road/transportation options (e.g., watercraft).
$
d. Establish a plan to fill finished water storage tanks to capacity prior to a storm event
$
e. Stock spare parts to repair damaged equipment.
$-$$
f. Explore interconnections or other partnership opportunities to share resources or facilitate emergency public water supply services with neighboring water utilities.
$$-$$$
Flood Mitigation for Water Intake, Distribution and Storage of Groundwater Utilities
1. Prevent well field/pump house from flooding.
Cost
a. Procure temporary flood barriers (e.g., sandbags) for use in minor floods.
$
b. Re-grade land surrounding well field so that it slopes away to prevent flood water from flowing toward the wells. Ensure that the casing terminates at least twelve inches above grade. Also, extend well casings above the flood zone.
$-$$
c. Relocate or elevate well field pump houses that are in the flood zone.
$$$
2. Protect critical components if groundwater intake and supply do flood.
a. Seal the top of well casings, waterproof well caps that are in the flood zone and extend vents above the flood zone elevation.
$
b. Periodically evaluate the integrity of surface seals outside casings and check that there has been no soil settling or that no cavity has developed around the outside of well casings where surface water would be able to flow down to the aquifer
$
c. Install submersible pumps or waterproof pump motors and other equipment.
$$
3. Maintain delivery of suitable process water during flooding.
a. Plan to fill water storage tanks to capacity prior to a storm event.
$
b. Have an alternative access plan in case normal access to wellhead/pump house is blocked. Consult with other entities (e.g., Department of Transportation) to consider alternate road/transportation options (e.g., watercraft).
$
Flood Mitigation for Booster Stations and Other Pumps
1. Prevent booster stations from flooding.
Cost
a. Procure temporary flood barriers (e.g., sandbags) for use in minor floods.
2. Protect critical components if booster stations do flood.
a. During upgrades or design of new equipment, develop capability to temporarily remove and safely store vulnerable components in advance of a flood.
$-$$$
b. Waterproof, relocate or elevate motor controls, variable frequency drives, computers and electrical panels to a higher elevation by constructing platforms or integrating controls into existing buildings or infrastructure on-site.
$$
c. De-energize systems prior to flooding to mitigate damage to electrical components.
$
d. Replace non-submersible pumps with submersible pumps, if cost effective.
$$-$$$
e. Replace standard electrical conduits with sealed, waterproof conduits. Replace electrical panels with submersion rated enclosures.
$$$
f. Install sump pumps for below-ground facilities. Although not typically used to protect against flooding events, sump pumps may provide additional time to take other mitigation measures.
$
g. Replace a below-grade booster station with an above-grade station elevated higher than the flood stage
$$$
3. Maintain pumping operations when the electrical grid is down.
a. Store temporary or replacement pumps out of the flood zone.
$
b. Install energy efficient equipment to increase the longevity of the fuel supply for backup generators.
$$
c. Replace pumps with diesel driven or dual-option counterparts.
$$
d. Consider options for procuring generators (permanent or portable) or an alternative energy supply.
$$
4. Maintain pumping operations.
a. Maintain a call list of multiple vendors that can provide “pump around” services in an emergency or enter into an agreement with one.
$
b. Procure extra portable pumps or specialized parts to repair damaged pumps. Consider stockpiling major components of specialized high capacity pumps.
$$-$$$
Flood Mitigation for Process Water Treatment Plant
1. Prevent structures from flooding.
Cost
a. Install physical barriers to protect the entire facility from flooding (e.g., flood walls, levees) or be able to deploy temporary systems that achieve the requiredprotection.
$$-$$$
b. Install green infrastructure within or beyond the boundaries of the treatment plant to attenuate, divert or retain flood water and storm surges.
$$-$$$
c. Install flood water pumping systems and/or channel/culvert systems to collect and divert flood water away from treatment processes.
$$
2. Protect critical components if the treatment plant does flood.
a. During upgrades or design of new equipment, develop capability to temporarily remove and safely store vulnerable components before a flood when there is enough advanced notice to do so.
$-$$$
b. Install saltwater-resistant equipment and storage tanks (e.g., for chemicals and fuel)..
$$
c. Waterproof electrical components (e.g., pump motors, monitoring equipment) and circuitry.
$$
d. Elevate, relocate or cap individual assets to prevent damage from flood waters; vertically extend the walls of a treatment structure (e.g., basin, tank, filter) above flood stage; and/or flood-proof/seal structures to prevent seepage of flood water into the treatment train.
$$$
e. Replace motorized and electrical equipment with submersible equipment (e.g., submersible pumps).
$$$
3. Maintain delivery of suitable process water during flooding.
a. Monitor the quality of raw water entering the treatment plant and be prepared to adjust the treatment process as necessary (e.g., chemical addition, residence time) to account for higher contaminant loading or increased turbidity.
$
b. Purchase portable, handheld testing equipment to serve as a backup to permanent mounted testing equipment that may be inoperable during a flood.
$
c. Develop process guidelines or models to understand potential water quality changes, adjustments that may have to be made to attain suitable process water standards and the potential costs of changes in treatment.
$$
d. Explore interconnections or other partnership opportunities to share resources or facilitate emergency public water supply services with neighboring water utilities.
$$-$$$
4. Maintain operation of treatment plant if electrical grid is down.
a. Install energy-efficient equipment to increase the longevity of the fuel supply for backup generators.
$$
b. Replace motorized equipment with diesel-driven or dual-option counterparts.
$$
5. Increase storage capacity in preparation for floods.
a. Consider filling finished water storage tanks to capacity prior to a storm event to maximize storage if service is interrupted or if the utility is damaged.
$
b. Install larger capacity chemical storage tanks to ensure a sufficient supply through and beyond an emergency until the supply chain is restored.
$$
c. Determine if increased finished water emergency storage capacity would be beneficial (as opposed to water age/quality concerns).
